Motor grader blade-shifting hydraulic actuator and mount therefor

ABSTRACT

A motor grader includes a circle frame on which a blade is linearly shiftably mounted. For selectively shifting the blade, there is provided a reciprocable hydraulic motor of the doublerod-end-type. The cylinder of the hydraulic motor is fixed to the drawbar frame and the opposite piston rod ends are attached to the rear side of the blade, the attachment being made by respectively disposing a pair of pins, which are integral with the blade, in openings which are in the opposite piston rod ends and elongated in the direction of shifting. The pins are disposed in the elongate openings such that the piston rod means is in tension during actuation of the hydraulic motor.

United States Patent [1 1 Hanser et al.

[ Feb.4,1975

[75] Inventors: Paul Edmund Hansel, Moline, lll.;

Thomas Edward Gebauer, Dubuque, Iowa [73] Assignee: Deere & Company, Moline, lll.

[22] Filed: Dec. 26, 1973 [21] Appl. No.: 427,467

[56] References Cited I UNITED STATES PATENTS Keusder 172/476 X 3,465,829 9/1969 Fisher et al. l72/793 X Primary ExaminerStephen C. Pellegrino [57] ABSTRACT A motor grader includes a circle frame on which a blade is linearly shiftably mounted. For selectively shifting the blade, there is provided a reciprocable hydraulic motor of the double-rod-end-type. The cylinder of the hydraulic motor is fixed to the drawbar frame and the opposite piston rod ends are attached to the rear side of the blade, the attachment being made by respectively disposing a pair of pins, which are integral with the blade, in openings which are in the opposite piston rod ends and elongated in the direction of shifting. The pins are disposed in the elongate openings such that the piston rod means is in tension during actuation of the hydraulic motor.

5 Claims, 5 Drawing Figures BACKGROUND OF THE INVENTION The present invention relates to a motor grader blade assembly and more particularly relates to a hydraulic motor and the mounting for the hydraulic motor for connecting the motor to the grader blade for reciprocating the same. I

It is common practice to provide a motor grader with a circle frame on which a blade is linearly shiftably or reciprocably mounted and to provide a two-way hydraulic motor for selectively effecting the shifting movement of the blade. These hydraulic actuators are usually of a standard type including a cylinder which is fixed I to the drawbar frame and a piston rod which projects from one end of the cylinder and is connected to the blade. The large amount of blade side-shift travel needed on large graders makes the use of these standard hydraulic motors impractical since long lengths of the rod are required to be exposed resulting in the rods being vulnerable to buckling when impact loads are imposed on the ends of the blades. To reduce the problem of buckling, rods of a large diameter may be used; however, this solution to the problem is quite costly.

SUMMARY OF THE INVENTION According to the present invention, there is provided a motor grader blade assembly including a blade and a two-way hydraulic actuator for shifting the blade constructed such that long lengths of actuator rod are not exposed and such that the hydraulic motor is not subjected to loads which would tend to buckle the actuator rod means thereof.

It is an object of the invention to provide a two-way hydraulic motor of the single-piston, double-rod-endtype and to mount the hydraulic motor on the motor grader so as to always be in tension during shifting of the grader blade and so as to remain unaffected by blade deflections caused by impact loads imposed on the ends thereof. More specifically, it is an object to provide such a hydraulic motor wherein the opposite ends of the rod means contain openings elongated in the direction of reciprocation of the rod means, the motor being mounted on the motor grader through means fixing the cylinder of the motor to the frame, which carries the blade, and a pair of pins which are fixed to spaced locations on the grader blade and respectively received in the elongated openings.

These and other objects will be apparent from the ensuing description and the appended drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view of a motor grader of the type embodying the present invention.

FIG. 2 is an end view of the blade showing its connection with the grader drawbar frame shown in FIG. 1.

FIG. 3 is a rear elevational view of the blade showing the hydraulic motor connected thereto.

FIG. 4 is a longitudinal sectional view of the hydraulic motor.

FIG. 5 is a somewhat schematic view showing the relative positions occupied by one end of the piston rod means and one end of the grader blade when the latter is deflected.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to H0. 1, therein is shown a motor grader designated in its entirety by the reference numeral 10. The motor grader 10 includes a fore-and-aft extending main frame 12 having a horizontal rear portion supported upon two pairs of rear wheels 14 and 16, respectively, and having a forward end supported upon' a front pair of wheels 18. The frame 12 is elevated between the pairs of wheels 14 and 16 and positioned therebeneath is a drawbar frame 20 having its forward end connected adjacent the front wheels 18, as at a universal connection 22, and having its rearward end supported from the main frame through means of a plurality of hydraulic motors, two of which are shown at 24 and 26, respectively. A circle frame 28 is rotatably mounted on the drawbar 20 by conventional means, not shown. Depending from the opposite sides of the circle frame 28 are a pair of support members, only one of which is shown at 30. An earth-working blade 32 is connected to the support members 30. The blade 32 is generally rectangular in the rear elevational view, as can best be seen in FIG. 3, and includes a guide rail 34 secured to its rear side and defining upper and lower recesses which are parallel and extend lengthwise of the blade. The support members 30 each carry removable clamp means 36 which engage the guide rail so as to permit the blade to be linearly shifted or reciprocated.

A hydraulic motor 38 is provided for selectively shifting or reciprocating the blade 32. The motor 38 includes a cylinder 40 which extends between and is fixed to the support members 30, in a manner not shown. As can best be seen in FIG. 4, a piston is slidably mounted in the cylinder and is threadably connected to the inner ends of rightand left-hand piston rods 52 and 54, respectively. To prevent the pistons from rotating when the motor 38 is installed, a pin 56 secures the piston 50 to the right rod 52. The outer ends of the piston rods 52 and 54 are respectively provided with openings 58 and 60, respectively, which are elongated in the direction of reciprocation of the piston 50. Rightand left-hand pins 62 and 64 are fixed to the rear side of the blade 32 and are respectively received in the openings 58 and 60. An important feature of the invention is the fact that the pins 62 and 64 are respectively located in those ends of the openings 58 and which are the most remote from the cylinder 40. Thus, the rod means defined by the piston 50, the right rod 52 and the left rod 54 is always in tension when the hydraulic motor 38 is actuated to shift the blade 32. Further, as can best be seen in FIG. 5, the blade 32 may be deflected by loads imposed on its end without the loads being transferred to the hydraulic motor 38.

In operation then, it will be appreciated that to shift the blade rightwardly from the position it occupies in FIG. 3, it is necessary only to pressurize the left side of the cylinder 40 while concurrently exhausting the right side thereof. This will cause the piston 50 to travel rightwardly which in turn will cause the blade 32 to be pulled rightwardly through the connection of the left piston rod 54 with the left pin 60, the piston rod 54 and the piston 50 thus being placed in tension. Leftward shifting of the blade 32 is, of course, accomplished by pressurizing the right end of the cylinder 40 while concurrently exhausting the left end thereof.

It may be desired to adjust the pistons between the rod end openings 58 and 60 to compensate for wear or for manufacturing tolerances and this can be accomplished easily by threading the left piston rod 54 into or out of the piston 50 before the hydraulic motor 38 is installed. Once the motor is installed, it will be appreciated that the pin 56 prevents the piston 50 from turning relative to either of the piston rods 52 and 54.

If the right end of the blade should become loaded such that it is caused to deflect rearwardly in the manner illustrated in FIG. 5, the pin 62 will move freely within the clearance provided by the elongated opening 58 in the end of the piston rod 52. This deflection, of course, will result in a tensile force being applied to the piston rod 54 through means of the left pin 64 but in no way is the rod means defined by the piston 50 and the piston rods 52 and 54 ever placed in compression so as to cause bending of the piston rod means.

l claim:

1. A motor grader blade assembly comprising: a support frame; an elongate blade having front and rear sides; mounting means securing said blade to said frame for substantially linear guided movement in the direction of the length of said blade; a linear actuator means being fixed to said frame adjacent said blade and including a unitary reciprocable rod means oriented for movement lengthwise of said blade and having opposite concurrently shiftable ends; connection means securing the opposite ends of said rod means to said blade and acting so as to maintain said rod means in tension during reciprocating movement and during times when an end portion of the blade is deflected rearwardly within predetermined limits.

2. The blade assembly defined in claim 1 wherein said connection means includes first and second apertures respectively located at the opposite ends of said rod means and each being elongated in the direction of reciprocation of said rod means; and first and second pins being fixed to said blade and respectively received in said first and second apertures.

3. The blade assembly defined in claim 2 wherein said linear actuator means is a hydraulic motor having a cylinder fixed to said frame; said rod means including a piston slidably mounted in said cylinder.

4. The blade assembly defined in claim 1 wherein said rod means includes first and second rods respectively connected to said piston; and at least one of said rods being fixed to said piston so as to prevent relative movement between said piston and piston rods.

5. The blade assembly defined in claim 2 wherein said linear actuator means is positioned behind the blade adjacent the rear side thereof and said first and second pins are fixed to the rear side of said blade. 

1. A motor grader blade assembly comprising: a support frame; an elongate blade having front and rear sides; mounting means securing said blade to said frame for substantially linear guided movement in the direction of the length of said blade; a linear actuator means being fixed to said frame adjacent said blade and including a unitary reciprocable rod means oriented for movement lengthwise of said blade and having opposite concurrently shiftable ends; connection means securing the opposite ends of said rod means to said blade and acting so as to maintain said rod means in tension during reciprocating movement and during times when an end portion of the blade is deflected rearwardly within predetermined limits.
 2. The blade assembly defined in claim 1 wherein said connection means includes first and second apertures respectively located at the opposite ends of said rod means and each being elongated in the direction of reciprocation of said rod means; and first and second pins being fixed to said blade and respectively received in said first and second apertures.
 3. The blade assembly defined in claim 2 wherein said linear actuator means is a hydraulic motor having a cylinder fixed to said frame; said rod means including a piston slidably mounted in said cylinder.
 4. The blade assembly defined in claim 1 wherein said rod means includes first and second rods respectively connected to said piston; and at least one of said rods being fixed to said piston so as to prevent relative movement between said piston and piston rods.
 5. The blade assembly defined in claim 2 wherein said linear actuator means is positioned behind the blade adjacent the rear side thereof and said first and second pins are fixed to the rear side of said blade. 